This application claims the priority benefit of Taiwan application serial no. 87218559, filed Nov. 9, 1998, the full disclosure of which is incorporated herein by reference.
1. Field of Invention
The present invention generally relates to a solder-hole layout for expansion slots on a circuit board, and more particularly to a solder-hole layout that can be electrically connected to one of various types of expansion slots on a circuit board.
2. Description of Related Art
An industrial standard adapter (ISA) slot has been used as an interfacing standard for personal computers for quite a long time. Due to its low access speed, it has gradually become obsolete. On the other hand, peripheral component interconnect (PCI) slots as well as other expansion slots are becoming more and more popular because of their advantages over the ISA slot. However, the demand for the ISA slot as a connection to some expansion equipment still exists in the industry. Therefore, the ISA slots are still required in practice. Unfortunately, the demand for the ISA slots varies depending on actual requirements. As a result, various types of expansion slots, including the ISA slots, in different quantities need to be built on circuit boards during the transition period to meet users"" requirements.
FIG. 1 is a portion of a motherboard showing a conventional solder-hole layout for expansion slots. There are two solder-hole layouts 12 and 14 for ISA slots, and one solder-hole layout 10 for a PCI slot. Since customers might require different types of expansion slots in different quantities, the manufacturer therefore needs to provide a motherboard with one ISA slot and two PCI slots or other combinations. Therefore, various products need to be designed and manufactured, and consequently extra stocks need to be carried. Also, development costs and time as well as the effort to manage the stock level are inevitably increased.
To meet users"" requirements for various types of expansion slots in different quantities, a motherboard accommodating various types of expansion slots needs to be built. Unfortunately, the number of connector ports on the chassis of a computer is limited. The relative positions of the connector ports are also fixed. It is unlikely that an unlimited number of expansion slots would be built on the motherboard.
A more practical way to solve the above-mentioned problem is to design a solder-hole layout on the motherboard, which solder-hole layout can be shared by the ISA and PCI slots. By doing so, the motherboard becomes compatible with different types of interfacing cards. Consequently, the developing costs can be reduced and the problem of stock management can be overcome. FIG. 2 is a portion of a circuit board showing a solder-hole layout for expansion slots, which causes a conflict because of the overlapping of solder holes in two different solder-hole layouts. As shown in FIG. 2, there is a solder-hole layout 30 for an ISA slot and a solder-hole layout 40 for a PCI slot. However, the chassis has only a limited number of connector ports with fixed positions through which expansion equipment can connect to the interfacing cards on the motherboard. It is necessary to align the interfacing cards to the connector ports on the chassis so that expansion equipment can be correctly connected to the interfacing cards. It is then difficult to put together the solder-hole layout 30 for the ISA slot and the solder-hole layout 40 for the PCI slot without conflicts because solder holes in a solder-hole row 34 of the solder-hole layout 30 overlap with those of a solder-hole row 42 of the solder-hole layout 40. It is then difficult for different types of expansion slots to share the same circuit board. As a result, different circuit boards need to be designed and manufactured for various combinations of different types of expansion slots required.
As a summary, the conventional solder-hole layout for expansion slots on a circuit board has the following disadvantages:
1. The chassis has only a limited number of connector ports with fixed positions through which expansion equipment can connect to the interfacing cards on the circuit board. It is necessary to align the interfacing cards to the connector ports on the chassis so that expansion equipment can be connected to the interfacing cards. Therefore, types and quantities of expansion slots which can be built on a circuit board are heavily constrained. Extra developing effort and manufacturing costs to design the circuit board layouts are required.
2. It becomes unavoidable to have at least two circuit board designs for every product developed during the transition period, which causes extra developing time and costs. This significantly prevents the products from being quickly and smoothly introduced into the market. Extra costs for stock management are also incurred.
It is therefore an objective of the present invention to provide a dual solder-hole layout for expansion slots, in which a plurality of solder holes are arranged in a specific way. One of the various types of expansion slots can be electrically connected to the dual solder-hole layout, which comprises a first solder-hole layout (70) and a second solder-hole layout (80). The first solder-hole layout (70) comprises a first solder-hole row (72) and a second solder-hole row (74). The second solder-hole layout (80) comprises a third solder-hole row (82) that is parallel to the first solder-hole row (72). Solder holes in the first solder-hole row form a straight line. The second solder-hole row (74) is separated into a first solder-hole portion (74a) and a second solder-hole portion (74b). The first solder-hole portion (74a) of the second solder-hole row (74) is closer and parallel to the first solder-hole row (72). The second solder-hole portion (74b) of the second solder-hole row (74) is also parallel to the first solder-hole row (72) but far from the first solder-hole row (72). The third solder-hole row (82) is parallel to the first solder-hole row (72) and the first solder-hole portion (74a) of the second solder-hole row (74).
Note that solder-hole rows of the dual solder-hole layout according to the preferred embodiment of the present invention can have different shapes, for example, a curved shape. This kind of dual solder-hole layout for expansion slots also comprises a first solder-hole layout and a second solder-hole layout, each comprising a plurality of solder holes. The first solder-hole layout can be electrically connected to a first slot, while the second solder-hole layout can be electrically connected to a second slot. The first solder-hole layout comprises a first solder-hole row and a second solder-hole row. The second solder-hole layout comprises a third solder-hole row. The dual solder-hole layout can electrically connect to either the first slot or the second slot at one time.
By using the dual solder-hole layout in which solder holes in the first and second solder-hole layouts are tightly arranged, the layout space required on the circuit board can be reduced. Working together with expansion slots having different pin configuration, various types of expansion slots can share a circuit board with the same solder-hole layout.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.